"Lo, children are a heritage of the LORD," Dr. Petit Tweeted the Psalm in response to one follower's excited congratulations. "And the fruit of the womb is his reward."

Equally ecstatic were his former in-laws and friends of the couple, who married last August.

"We are very happy for them," says the Rev. Richard Hawke, father of Jennifer Hawke-Petit, Dr. Petit's late wife. "He is too young to go through life by himself."

He thinks his daughter and granddaughters would approve as well.

"They were certainly the kind of people that looked out for others," he says. "I think they would be pleased. He'll always have a space in his heart for them."

Dr. Petit was a caring and involved father to Michaela, 11, and Hayley, 17, and will surely be the same with his new son or daughter, Hawke adds.

"He was constantly teaching them," says Hawke, 82. "He was always taking whatever opportunity he had to make sure that the children learned from that experience."

Ann Baldwin, who's known Christine and Dr. Petit for several years, last saw them at Christine's art show in West Hartford, Conn. July 25. Christine is a professional photographer and was displaying some of her work.

"I saw a glow of happiness that was indescribable," says Baldwin. "She was just beaming. He was smiling and upbeat. It's just fantastic."

Baldwin says Dr. Petit is the happiest she's seen him since the July 2007 tragedy that took his family from him.

"After seeing him in other situations," she says, "it felt good for me to see him happy."